Event Notification Report for May 26, 2000
U.S. Nuclear Regulatory Commission Operations Center Event Reports For 05/25/2000 - 05/26/2000 ** EVENT NUMBERS ** 36888 37031 37032 37033 37034 +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 36888 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: WATERFORD REGION: 4 |NOTIFICATION DATE: 04/13/2000| | UNIT: [3] [] [] STATE: LA |NOTIFICATION TIME: 17:13[EDT]| | RXTYPE: [3] CE |EVENT DATE: 04/13/2000| +------------------------------------------------+EVENT TIME: 15:35[CDT]| | NRC NOTIFIED BY: E. LEMKE |LAST UPDATE DATE: 05/25/2000| | HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: N/A |CHARLES PAULK R4 | |10 CFR SECTION: | | |AINC 50.72(b)(2)(iii)(C) POT UNCNTRL RAD REL | | |AOUT 50.72(b)(1)(ii)(B) OUTSIDE DESIGN BASIS | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ |3 N Y 100 Power Operation |100 Power Operation | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | FEEDWATER ISOLATION VALVES MAY CLOSE FASTER THAN 1.5-SECOND DESIGN BASIS | | LIMIT. | | | | On March 21, 2000, Waterford Unit 3 determined that, based on a new | | calculation methodology and the latest stroke time data, the Feedwater | | Isolation Valves (FWIVs) FW-184 A (B) may close faster than the 1.5-second | | design basis limit. | | | | The physical plant was determined to be operable and the FWIVs would have | | performed their intended safety function at the time the condition was | | identified. An initial operability evaluation was made in accordance with | | procedure W4.101, which determined that the valves were operable at the time | | the evaluation was conducted. This was based on an engineering evaluation | | that determined that the faster closure of the FWIVs would not result in | | water hammer loads that would prevent the FWIVs and their associated | | penetrations from performing their required safety function. The | | engineering evaluation determined that the analyzed increase in fast valve | | closure (FVC) load is 57% for FW-184A and 52.9% for FW-184B. | | | | A subsequent evaluation was performed for FW-184A (B) to determine if at any | | time in the last two years the increase in FVC load may have exceeded the | | allowable loads determined by the engineering evaluation for W4.101. That | | evaluation determined on one occasion for FW-184A and six occasions for | | FW-184B, the percent increases for the FWIVs and subsequent stroke times | | exceeded the values provided in the operability determination | | | | On these occasions in question, closure of FW-184A (B) in response to the | | most adverse accident scenario could have potentially produced water hammer | | that may have exceeded the capability of piping supports in the FW system | | between the SGs and FW-184A (B). This may have resulted in the subsequent | | loss of containment isolation function of FW-184A (B). | | | | The NRC Resident Inspector was notified of this event by the licensee. | | | | * * * UPDATE ON 05/25/00 AT 1630 ET BY CHRIS PICKERING TAKEN BY MACKINNON * | | * * | | | | Entergy is revising this event notification. The event was initially | | reported under 10CFR50.72(b)(2)(iii) as a condition that alone could have | | prevented fulfillment of a safety function. Based upon further review of | | the condition, Entergy has determined the condition is reportable under | | 10CFR50.72(b)(1)(ii)(B) as a condition that was outside the design basis of | | the plant. | | | | Evaluation of the event determined that the potential impact on containment | | integrity as a result of this condition does not affect the results of the | | currently analyzed MSLB event's radiological consequences. Further, the | | possibility of containment integrity loss due to excessive waterhammer loads | | during a FWLB remains bounded by the MSLB with respect to dose consequences. | | The FWLB event radiological consequences are bounded by the MSLB event, | | which is predicted to be within 10CFR100 limits. | | | | This event posed a containment integrity condition that was outside the | | design basis of the plant. An evaluation determined that the FWIVs could | | have potentially closed faster than their design basis minimum limit on | | seven occasions, six instances for FW-184A and one instance for FW-184B. | | The original event notification (above) incorrectly noted that there was one | | instance for FW-184A and six instances for FW-184B. The faster valve | | closure times could have placed increased loads on the piping and piping | | supports in the FW system between the steam generators (inside containment) | | and the FWIVs (outside containment). These increased loads were not | | accounted for in the design basis of the system. Based on this information, | | the event is reportable under 10CFR50.72(b)(1)(ii)(B) as a condition that | | was outside the design basis of the plant. | | | | The NRC Resident Inspector was notified of the event revision by the | | licensee. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 37031 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: CATAWBA REGION: 2 |NOTIFICATION DATE: 05/25/2000| | UNIT: [1] [] [] STATE: SC |NOTIFICATION TIME: 09:21[EDT]| | RXTYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 05/25/2000| +------------------------------------------------+EVENT TIME: 08:32[EDT]| | NRC NOTIFIED BY: KEVIN PHILLIPS |LAST UPDATE DATE: 05/25/2000| | HQ OPS OFFICER: FANGIE JONES +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: N/A |MARK LESSER R2 | |10 CFR SECTION: | | |AOUT 50.72(b)(1)(ii)(B) OUTSIDE DESIGN BASIS | | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ |1 N Y 100 Power Operation |100 Power Operation | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUXILIARY BUILDING FILTERED EXHAUST MAY NOT HAVE BEEN ABLE TO PERFORM ITS | | DESIGN FUNCTION | | | | The licensee discovered both doors on the vestibule to the '1A' Centrifugal | | Charging Pump Room not fully closed, this may have prevented the Auxiliary | | Building filtered exhaust system from maintaining a negative pressure in | | that room. This would render both trains of Auxiliary Building exhaust | | inoperable per Technical Specifications 3.7.12 and would require entry into | | Technical Specification 3.0.3. The doors were closed on discovery which | | returned the unit to compliance with Technical Specifications. | | | | The licensee will followup with an investigation into when and how the doors | | came to be open. | | | | The licensee notified the NRC Resident Inspector. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 37032 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: MCGUIRE REGION: 2 |NOTIFICATION DATE: 05/25/2000| | UNIT: [1] [] [] STATE: NC |NOTIFICATION TIME: 21:47[EDT]| | RXTYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 05/25/2000| +------------------------------------------------+EVENT TIME: 20:46[EDT]| | NRC NOTIFIED BY: H. M. HARRIS |LAST UPDATE DATE: 05/25/2000| | HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: N/A |MARK LESSER R2 | |10 CFR SECTION: |JOHN HANNON NRR | |ARPS 50.72(b)(2)(ii) RPS ACTUATION |JOSEPH GIITTER IRO | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ |1 A/R Y 100 Power Operation |0 Hot Standby | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | TURBINE RUNBACK TO 50% DUE TO LOSS OF A MAIN FEEDWATER PUMP FOLLOWED BY A | | REACTOR TRIP ON LOW LOW STEAM GENERATOR WATER LEVEL. ONE AUXILIARY | | FEEDWATER PUMP HAD TO BE MANUALLY STARTED. | | | | Reactor automatic trip occurred at 2046 ET. Initiating event was steam | | generator low low water level on "C" steam generator. Prior to the trip | | Channel 1 vital 120 volt AC power was lost due to the tripping open of EVIA | | (DC/AC ) inverter AC output breaker. No testing was in progress at this | | time and the cause of the AC breaker trip is under investigation. When the | | AC output breaker opened it caused a loss of Channel 1 power. Main | | feedwater pump "1A" control circuitry interfaces with Channel 1 120 volt AC | | power and when Main Feedwater pump "1A" control circuitry power was lost | | main feedwater pump "1A" turbine tripped. The loss of Main Feedwater pump | | "1A" turbine initiated an automatic main turbine runback to 50% power. | | After the main turbine runback to 50% power the reactor tripped on steam | | generator "1C" low low water level. Only one of two motor driven auxiliary | | feedwater pumps automatically started on steam generator "1C" low low water | | level. Auxiliary feedwater pump "1A" was manually started approximately 2 | | minutes after the automatic reactor trip. The licensee is investigating why | | the "1A" auxiliary feedwater pump did not automatically start. All rods | | fully inserted into the core and reactor coolant temperature is being | | maintained at Tave no load condition of 557 degrees F. No PORVs or code | | safety valves on either the primary or secondary side of the plant opened. | | All the Emergency Core Cooling Systems and the Emergency Diesel Generators | | are fully operable if needed. Offsite electrical grid is stable. The | | licensee's investigation into the initiating event is continuing. | | | | The NRC Resident Inspector was notified of this event by the licensee. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Fuel Cycle Facility |Event Number: 37033 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: PORTSMOUTH GASEOUS DIFFUSION PLANT |NOTIFICATION DATE: 05/25/2000| | RXTYPE: URANIUM ENRICHMENT FACILITY |NOTIFICATION TIME: 23:52[EDT]| | COMMENTS: 2 DEMOCRACY CENTER |EVENT DATE: 05/25/2000| | 6903 ROCKLEDGE DRIVE |EVENT TIME: 18:00[EDT]| | BETHESDA, MD 20817 (301)564-3200 |LAST UPDATE DATE: 05/26/2000| | CITY: PIKETON REGION: 3 +-----------------------------+ | COUNTY: PIKE STATE: OH |PERSON ORGANIZATION | |LICENSE#: GDP-2 AGREEMENT: N |JOHN MADERA R3 | | DOCKET: 0707002 |WAYNE HODGES NMSS | +------------------------------------------------+ | | NRC NOTIFIED BY: JIM MCCLEERY | | | HQ OPS OFFICER: FANGIE JONES | | +------------------------------------------------+ | |EMERGENCY CLASS: N/A | | |10 CFR SECTION: | | |NBNL RESPONSE-BULLETIN | | | | | | | | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | NRC BULLETIN 91-01, 24 HOUR NOTIFICATION | | | | The following is the faxed report from Portsmouth: | | | | On May 16, 2000, PORTS plant personnel initiated a review of an NRC event (# | | 36993) submitted by Paducah Gaseous Diffusion Plant (PGDP), to assess | | applicability at the Portsmouth sight. Errors associated with calibration | | correction factors used to determine uranium masses were found to have not | | occurred at the PORTS sight. | | | | On May 25. 2000, after further review by Nuclear Criticality Safety dept. | | personnel, a violation of double contingency was identified when it was | | determined that the independence of non-destructive assay (NDA) measurements | | was not maintained. NCSA-PLANT013.A00 indicated that NDA measurements will | | be maintained independent. However, calibration of instruments was not | | maintained independent and therefore the resulting measurements were not | | independent. As a result, the calibration process failed to ensure that a | | single failure could not effect two independent mass measurements. Double | | contingency was violated in cases where two independent uranium mass | | measurements were required to establish double contingency. | | | | A review of NDA calibration data confirmed that no measurement errors | | actually existed which would have affected the mass readings taken to | | establish double contingency. This event is being reported because the | | independence or mass measurement readings was not established and | | maintained. | | | | SAFETY SIGNIFICANCE OF EVENTS: | | | | The safety significance of this event is very low. All historical | | calibrations were reviewed (Ref. POEF-38.340.00.086) and no discrepancies | | were identified with historical measurements. Furthermore, ongoing | | laboratory Quality Assurance programs and practices help ensure errors of | | this nature remain sufficiently unlikely to be relied on as criticality | | controls. | | | | | | POTENTIAL CRITICALITY PATHWAYS INVOLVED (BRIEF SCENARIO[S] OF HOW | | CRITICALITY COULD OCCUR): | | | | An error in NDA measurements plus uncertainty would have to be low by | | greater than a factor of two or results in a critical mass of uranium going | | undetected. if this mass were then subject to the correct geometry, | | moderation and reflection conditions a criticality could error | | | | | | CONTROLLED PARAMETERS (MASS, MODERATION, GEOMETRY, CONCENTRATION, ETC.): | | | | Mass is the only controlled parameter. Two independent measurements of mass | | are required to ensure double contingency. Since independence of NDA of NDA | | mass measurements is called Into question, only one independent estimate of | | mass is available. The absence of a second independent NDA mass measurement | | represents a loss of one double contingency control. | | | | | | ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS | | LIMIT AND % WORST CASE OF CRITICAL MASS): | | | | No uranium was involved in the event. NDA measurements are used to classify | | cascade deposits as either greater than safe mass or less than safe mass. | | (Safe Mass is 43.5% of minimum critical mass.) NDA measurements are also | | used in batching operations to ensure the 235U mass in the final container | | is less than 350 grams 235U which is less half the minimum critical mass at | | 100% enrichment and optimum moderation, geometry and reflection conditions. | | | | | | NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION | | OF THE FAILURES OR DEFICIENCIES | | | | Nuclear criticality safety controls include independent mass measurements of | | 235U. Failure to ensure the calibration of the NDA instrumentation was | | independent lead to a potential failure of the mass measurements. | | | | | | CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEM AND WHEN EACH WAS IMPLEMENTED: | | | | NDA measurements performed for criticality safety purposes have been | | suspended until independent verification of calibration data requirements is | | flown into applicable procedures and programs. | | | | The certificate holder notified the NRC Resident Inspector and will notify | | the DOE representative. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 37034 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: HOPE CREEK REGION: 1 |NOTIFICATION DATE: 05/26/2000| | UNIT: [1] [] [] STATE: NJ |NOTIFICATION TIME: 02:29[EDT]| | RXTYPE: [1] GE-4 |EVENT DATE: 05/25/2000| +------------------------------------------------+EVENT TIME: 22:54[EDT]| | NRC NOTIFIED BY: CHRIS SERATA |LAST UPDATE DATE: 05/26/2000| | HQ OPS OFFICER: FANGIE JONES +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: N/A |DAN HOLODY R1 | |10 CFR SECTION: | | |AIND 50.72(b)(2)(iii)(D) ACCIDENT MITIGATION | | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ |1 N Y 15 Power Operation |15 Power Operation | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | FOUR FILTRATION RECIRCULATION AND VENTILATION FANS TRIPPED UNEXPECTEDLY | | | | "On 5/25/00 at 22:54 hours, four operating Filtration, Recirculation. and | | Ventilation System (FRVS) recirculation fans (A, B, D, E) unexpectedly | | tripped while they were running for a monthly surveillance. An FRVS | | ventilation fan, that was also in service, continued to run. | | | | "The FRVS consists of two subsystems, the Recirculation System and the | | Ventilation System. The FRVS Recirculation System is an Engineered Safety | | Feature (ESF) System, located inside the Secondary Containment, that reduces | | offsite doses significantly below 10CFR100 guidelines during a LOCA, | | refueling accident, or high radioactivity in the Secondary Containment. Upon | | a Secondary Containment isolation, the FRVS Recirculation System is actuated | | and recirculates the Secondary Containment air through filters for cleanup. | | This subsystem is the initial cleanup system before discharge is made via | | the FRVS Ventilation subsystem to the outdoors. The FRVS Ventilation System | | is an ESF system, located inside the Secondary Containment, that maintains | | the building at a negative pressure with respect to the outdoors. The system | | takes suction from the discharge duct of the FRVS Recirculation system and | | discharges the air through filters to the outdoors. | | | | "Investigation into the cause of the fan trips has identified a manual | | damper in the ventilation system ductwork that failed to the closed | | position. This manual damper is normally open during power operation. This | | damper is repositioned closed during refueling outages to redistribute | | ventilation through the Secondary Containment. Immediate actions were taken | | to return the damper to the open position. Recirculation fans have been | | returned to service and are operating satisfactorily. | | | | "The ventilation system ductwork was reviewed to identify other manual | | dampers that could have the same or similar affect on system operation. Two | | other dampers were identified, their positions have been verified to be | | correct. | | | | "Hope Creek is presently in Operational Condition 1 at 15% power with the | | turbine/generator off-line awaiting replacement of the 'C' Main Power | | Transformer. All safety related equipment is available." | | | | The fans had been operating about 10 hours before tripping, it is suspected | | that the damper was not adequately secured in the open position when the | | plant exited the refueling outage. The licensee is investigating. | | | | The licensee notified the NRC Resident Inspector and the local township | | authorities. | +------------------------------------------------------------------------------+
Page Last Reviewed/Updated Thursday, March 25, 2021
Page Last Reviewed/Updated Thursday, March 25, 2021